Answer
$\sqrt{5}.$
Work Step by Step
We know that if $k=ai+bj$ and $l=ci+dj$, then $k+l=(a+c)i+(b+d)j$ and that if $z$ is a constant, then $zk=(za)i+(zb)j$.
Also, the magnitude of a vector $v=ai+bj$ is: $||v||=\sqrt{a^2+b^2}$.
Hence here: $||v-w||=||(3i-5j)+(-2i+3j)||=||i-2j||=\sqrt{1^2+(-2)^2}=\sqrt{1+4}=\sqrt{5}.$